Feature request: Adding support for combo layers

[doesntfazer]

It would be cool to see combo layers working. I use them on all of my keyboards, but it doesn't look like you can add them manually without breaking POG.

[doesntfazer]

https://github.com/KMKfw/kmk_firmware/blob/main/docs/en/combo_layers.md

[doesntfazer]

I was able to get it working by adding it manually to the kb.py file.

    def __init__(self, features=['basic']):
        if "basic" in features:
            from kmk.modules.layers import Layers; self.modules.append(Layers())
            from kmk.extensions.media_keys import MediaKeys; self.extensions.append(MediaKeys())
            combo_layers = {
            (1, 2): 3,
            }
        self.modules.append(Layers(combo_layers))

[JanLunge]

I will test this on my board so we can ship some demo code in the kb.py until it is available in the gui as well